The Scottish League is currently completely FREE. To try it out, you have to register now or login if you already have an account. When your e-mail is validated you will automatically receive a working Demo API-Key.
Official .NET library - input your API-key and let the library parse XMLSoccer.com XML into objects.
Unofficially JAVA library - input your API-key and let the library parse XMLSoccer.com XML into objects.
Open Source (community created) PHP parser available on GitHub for you to fork.